Detergent processes



United States Patent 3,235,505 DETERGENT PROCESSES Melvin E. Tuveil, St. Ann, Mo., assignor to Monsanto Company, a corporation of Delaware N0 Drawing. Filed Sept. 20, 1961, Ser. No. 139,379 23 Ciainis. (Cl. 252-135) This invention relates to liquid detergent emulsion compositions. More specifically, the invention rel-ates to improved processes for preparing liquid detergent emulsion compositions that exhibit excellent stability against phase separation even though they contain relatively high concentrations of inorganic salts and of synthetic organic detergent active materials. The invention also relates to novel compositions lWhlCh are utilized in these improved processes.

The many benefits which can result from the utilization of effective detergent compositions that are liquid in form are widely appreciated. In order to be competitive with the well-known dry powdered or granulated detergents, liquid detergent compositions must contain high concentrations of both inorganic builder salts; for example, phosphates, silicates, carbonates and sulfates (usually dissolved in water); and organic detergent active materials. Because of the presence of high-concentrations of inorganic salts in water, very little, if any, of the organic detergent active material can actually be dissolved in water. Therefore, if a detergent manufacturer wishes to make a reasonably competitive liquid detergent, he must ordinarily either disperse or emulsify the detergent active material into the concentrated salt solution.

While the emulsification or dispersion per se of most detergent active materials in concentrated salt solutions is not difiicult, it has heretofore been very diflicult to manufacture liquid detergents containing such dispersed detergent active materials that are stable for an extended period of time against separation of the detergent active material from the concentrated salt portion of the detergent composition (i.e., stable against phase separation). Since consumers of liquid detergents generally feel that liquid detergents which separate are objectionable, it can readily be appreciated that manufacturers of concentrated liquid detergents have as one of their foremost objectives the production of liquid products that are stable against phase separation for as long a time as possible under any or all of the usual Warehousing, shipping, and storage conditions to which the liquid detergent compositions are exposed.

It is a primary object of this invention to provide a process for the preparation of concentrated liquid detergents having excellent stability against phase separation.

It is another object of this invention to provide novel compositions which can be used to manufacture highly stable liquid detergents.

The above objects as well as others, are accomplished in accordance with the present invention by emulsifying a detergent active material containing a polyoxyalkylene chain into a concentrated aqueous, inorganic salt solution while the detergent active material is in intimate contact with a hydrolyzed (acidic) polymer, and thereafter converting the polymer to the salt (alkaline) form.

One can employ in the practice of this invention, a solution of any inorganic or organic water-soluble salt which it is desired for building or for any other reason, to incorporate into a detergent composition, so long as the salt is compatible with the other components of the composition. Well known precautions should be observed in mixing the various materials in the practice of the invention. Ordinarily, the compatible salts that can be employed are those which are soluble in distilled water to the extent of at least about weight percent. And where 3,235,505 Patented Feb. 15, 1866 ice raw material cost considerations are important, these salts will be inorganic in nature. As a practical matter, however, because of economic considerations as well as the necessity to include in the liquid detergent compositions as high a level as is practicable of materials which can sequester hardness ions, such as calcium, magnesium, and iron, the salts which are preferably utilized are the alkali metal chain phosphate salts (such as, for example, the alkali metal pyrophosphates such as tetrasodium pyrophosphate, tetrapotassium pyrophosphate, etc.), the acid pyrophosphates such as disodium dihydrogen pyrophosphate, trisodium monohydrogen pyrophosphate, dipotassium d-ihydrogen pyrophosphate, etc., the tripolyphosphates and acid tripolyphosphates such as sodium tripolyphosphate (Na P O potassium tripolyphosphate (K P O tetrasodium monohydrogen tripolyphosphate (K HP O tripotassium dihydrogen tripolylphosphate (K li-1 1 0 etc., the alkali metal tetrapolyphosphates such as hexasodium and hexapotassium tetrapolyphosphate, etc., the alkali metal hexarnetaphosphates and higher chain length chain polyphosphates such as those that are present in the sodium, potassium, and lithium phosphate glasses (i.e., usually prepared by melting a mixture of phosphate salts having an M O/P O ratio between about 1.0 and about 1.3 where M is an alkali metal, and quenching the resulting product to yield a mixture of chain polyphosphate salts of varying molecular weight), and the like (wherein the particularly preferred alkali metal salts are potassium and sodium). Of these, tetrapotassium pyrophosphate is most preferred. Other watersoluble sequestering agents such as alkali metal ethylene diamine, alkali metal citrate, alkali metal tartrate, etc., can also be utilized to advantage in the composition. Since the alkali metal chain phosphate salts are preferred for purposes of this invention, their use will be discussed below. However, it should be understood that while reference is made specifically to the alkali metal chain phosphate salts, other inorganic salts, and water-soluble sequestering agents can generally be utilized either in place of all of the phosphate salt, in place of some of it, or in addition to it. Apparently the benefits which result from the utilization of concentrated solutions in the processes of the present invention result to some extent from their ability to salt out the detergent active material from the water (or in most instances contemplated herein) to prevent the detergent active material from dissolving to any great extent in the water.

Ordinarily, in the practice of the present invention, the salt solutions that are employed must be fairly concentrated in nature. The reason for this requirement has been found by the present inventor to be so that substantially none (i.e., less than about 2 and preferably less than about 1 weight percent) of the polyoxyalkylene detergent active material is dissolved in the solutions during the emulsification or dispersion step (which will be described in detail below) of the processes of the invention. Thus, the term concentrated salt solution as herein utilized will mean an aqueous solution of one or more of the salts described above which contains at least enough of the salt or salts dissolved therein to prevent a significant amount of the polyoxyalkylene detergent active material from dissolving in the solution. Ordinarily at least about '5 .and preferably at least about 10 weight percent of salts (dissolved in the solutions) are utilized for this purpose. Somewhat lower quantities of salts in the production of concentrated salt solution are required if a soluble polyelectrolyte salt such as one of the alkali metal chain phosphates described above is utilized. For example, only about 3 weight percent, but preferably at least about 5 weight percent of sodium acid pyrophosphate, tetrapotassium pyrophosphate, etc., dissolved in water makes an acceptable concentrated salt solution for use in the processes of the invention. Since the appearance of salt crystals in the final liquid detergent products is generally objectionable from an aesthetic point of view as well as detrimental to the stability (against phase separation) of the final liquid detergent compositions, ordinarily the concentrations of the various salts in the concentrated salt solutions .will be maintained at a level which is not sufficiently high to result in their crystallizing out of solutions when the detergent products made therefrom are handled and stored. Generally, concentrated salt solutions which do not precipitate any salt crystals when they are held at about 10 C. for an extended period of time are considered optimum in this respect.

The detergent active materials that have been found to be especially useful in the practice of the invention are those which are water-soluble (i.e., soluble in water to at least the extent of about .1.3 weight percent, which is about the concentration at which they will ultimately be utilized to wash clothes or dishes for example) and contain at least one polyoxyalkylene (from ethylene oxide, and/ or propylene oxide, and/ or butylene oxide, but preferably from ethylene oxide) chain having from about 5 to about 50, and preferably from about to about 25 oxyalkylene units in the chain. The polyoxyalkylene-type detergent active materials which are useful can be either nonionic or anionic in character. Typical examples of nonionic polyoxyalkylene detergent active materials which are preferred, include the condensation products of ethylene oxide and/or propylene oxide and/ or butylene oxide with an alkylphenol having an alkyl (hydrocarbyl) chain that contains from 6 to 20 carbon atoms; with a monohydric primary alcohol, which is preferably highly branched (such as those produced via the OX0 process), but can also have the straight chain configuration, wherein the alcohol contains from about 10 to about 18 carbon atoms; with fatty acids having from 10 to 18 carbon atoms including those derived from tall oil; with a fatty amine, for example n-dodecylamine; etc.

Examples of useful detergent active materials that are anionic in character, but also contain the required polyoxyalkylene chain, are the alkylene oxide-alcohol or -phenol condensates which have been sulfated, as for example, the sodium salt of sulfated tallow alcohol containing about 20 moles of ethylene oxide per mole of alcohol, the potassium salt of sulfated dodecylphenol containing about 8 moles of ethylene oxide per mole of phenol, the sodium salt of sulfonated dodecylbenzyl ether of phenol which has been condensed with about 20 moles of ethylene oxide per mole of phenol, and the like.

Generally, between about 2 weight percent and about 20 weight percent of these useful polyoxyalkylene detergent active materials will be present in the liquid detergent products that are made according to the processes of the invention. However, the better liquid detergent products will generally contain from about 4 to about weight percent of one or more of them. In addition, these useful nonionic and anionic polyoxyalkylene detergent active materials will ordinarily be utilized, in the practice of the present invention, in the liquid state. While most of the desired detergent active materials described above are liquids under ambient conditions, those that are not ordinarily liquids at room temperature can readily be melted by Warming them to about 50-60" C.

Minor proportions (as compared to the amount of the polyoxyalkylene detergent active materials that are utilized) of materials can be used to supplement the abovedescribed polyoxyalkylene detergent-active materials in the practice of the present invention. Typical of these other types are the detergent active or surface active aromatic sulfonates which are free of polyoxyalkylene chains, such as the sodium sulfonate of an alkylated aromatic hydrocarbon. These sulfonates are usually prepared by alkylating an aromatic hydrocarbon of the class consisting of benzene, toluene, xylene, for example, with aliphatic or olefinic hydrocarbons having from 9 to 18 carbon atoms, and then sulfonating and neutralizing the resulting alkylaromatic hydrocarbon. Another example of detergent-active materials that can supplement the poly oxyalkylene detergent active materials described hereinbefore are the alkylolamides having from 10 to 20 carbon'- atoms in the acid portion of the molecule. These alkylol-- amides are formed by reacting a fatty acid, such as tall oil fatty acid, coconut fatty acids, stearic acid, lauric etc., with an alkylolamine such as monoethanolamine, (li ethanolamine, monoisopropanolamine, diisopropanolamine, mono-n-propanolamine, di-n-propanolamine, etc. Ordinarily, these supplemental (to the polyoxyalkylcne materials) detergent active materials can be utilized in the compositions within the scope of this invention at levels of from a mere trace to several weight percent. However, the preferred liquid detergent compositions contain no more than about 40 weight percent of such supplemental materials based on the polyoxyalkylene detergent active material employed.

However, in some instances it is possible to prepare suitable liquid detergents by replacing all of the polyoxyalkylene detergent actives with one or more of the supplemental detergent active materials.

The excellent stability of the liquid detergents that are manufactured according to the processes of this invention is at least partially due to the particular polymer that is employed. Polymers that can be utilized in the practice of the invention are maleic polymers (polyelectrolytes) which result from the copolyrnerization in substantially equimolar proportions of maleic anhydride with a lower molecular weight olefinically unsaturated compound hav ing less than 5 carbon atoms. Examples of such co-' polymerizable lower molecular weight olefins are ethylene, propylene, isobutylene, vinyl methyl ether and the like. Ordinarily the molecular weight of the lower molecular weight olefins that can be used in the practice of this invention will be within the range of from about 26 to about 100, and preferably from about 26 to about 60. It will be noted that the lower molecular weight olefinmaleic anhydride polymers contemplated herein have a linear carbon chain backbone that consists of two alternating pairs of carbon atoms. Attached to one of these pairs of carbon atoms is a carboxylic anhydride radical, containing preferably two, but sometimes three carbon atoms, While attached to the second pair of carbon atoms in the polymer chain is a hydrocarbyl radical containing one or two carbon atoms; an ether radical containing, in addition to the oxygen atom, one or two carbon atoms; a methyl acetate radical; and/ or hydrogen. The linear polymers that result from polymerizing maleic anhydride with one of these copolymerizable lower molecular weight olefins can also be cross-linked with a diamine, an alkylene polyamine, or a diolefinic material such as an ether or a hydrocarbon, etc. Examples of polyamines which have been found to be particularly useful are diethylene triamine, triethylene tetramine, tetraethylene pentamine, and higher molecular weight polyethylene polylamines. Preferred diolefinic cross-linking materials include divinyl benzene, dially ether, vinyl crotonate, diallyl esters, and the like. .For a practical degree of emulsion stability in the final detergent products, however, the degree of crosslrnking in any given maleic polymer must be low enough to permit the polymer, after it has been hydrolyzed, to be soluble in water to the extent of at least about 1 weight percent. It has been found that mela-ic polymers, such as those described above, having molecular weights between about 1,000 and 100,000 can be used in the practice of the invention. For better stability maleic polymers having molecular weights of from about 1,200 to about 50,000 are preferred. These maleic polymers are generally manufactured in non-aqueous systems utilizing substantially unhydrolyzed maleic anhydride.

Methods for preparing most of the maleic polymers; that are useful in the practice of the present. inv ntion are well-known in the art, and thus, need not be detailed here. Methods for preparing some of the cross-linked polymers which were not known heretofore, can be found in two copending patent applications, Serial Numbers 763,796 and 763,828, filed September 29, 1958.

Through the polymerization process the anhydride portion of the maleic anhydride molecule remains practically unchanged. However, when the polymers are exposed to moisture, the anhydride portion is readily hydrolyzed to form carboxylic acid groups. Thus, depending upon the amount of humidity to which particular batches of these polymers have been exposed, commercially available maleic polymers can contain almost any proportion of their anhydride groups in the hydrolyzed, acidic form. For purposes of this invention, the term acidic maleic polymer will mean those maleic polymers in which more than half of, and preferably, in which substantially all of the anhydride groups contained therein are in the hydrolyzed, carboxylic acid form.

Usually these maleic polymers can be utilized in liquid etergent compositions at levels of from about 0.1 to about 8 weight percent, based on the weight of the final liquid detergent composition. For compositions having extremely good stability to phase separation along with good drainage characteristics (from a container such as, for example, a measuring cup), however, between about 0.25 and about 3 weight percent of one of the maleic polymers preferably should be contained therein.

The actual manipulative steps which are involved in the processes of this invention are believed to contribute unexpectedly to the achievement of the very stable emulsions that result from its practice. There are at least two essential steps or stages in the processes through which the various important raw materials must be passed if liquid detergent emulsions having excellent stability to phase separation are to be obtained. The first requlres that the maleic polymer be in intimate contact with the polyoxyalkylene detergent active material during the period of time in which the detergent active material is in its most finely divided state (in the concentrated salt solution). In order to meet this requirement, the polymer must either be in physical contact with the detergent active material when it is emulsified or it must I brought into intimate contact with the detergent active material practically immediately thereafter. Another requirement of the invention is that the maleic polymer be in the acid form at this time. The reason for the need to have the polymer in the acid form in this stage of the processes is believed to be, that in this form, a better a protective coating of polymer particles is formed on the surface of the emulsified detergent active material.

The emulsification of the polyoxyalkylene detergent active material (which is preferably fluid or in the liquid state at the time of said emulsification, and does not necessarily have to contain any or all of the maleic polymer dissolved therein) into the concentrated salt solution can be accomplished by utilizing any of a number of conventional mixing techniques whereby a great deal of shear is applied to the mass of active material. The emuslification can be accomplished, for example, by means of fairly efficient homogenizer, a colloid mill, or even a conventional relatively high-speed turbine-stator blade mixer. The most stable emulsions that have been made according to the invention have been found to contain extremely small particles of active material, e.g., about In or less in diameter. However, in order to appreciate the benefits of the invention, such extremely small particles as this do not have to be produced. Generally, for good results, the mechanical agitation which is applied during these processes in order to emulsify the active material into the concentrated salt solutions should be of sufficient intensity to produce particles (individual droplets) of the active material which are smaller than about 2 POLYMER IN DETERGENT ACTIVE METHOD One preferred method by which the maleic polymer (in the said acid form) is brought into intimate contact with the polyoxyalkylene detergent active material just at the time it is being emulsified into the concentrated salt solution is by the polymer having been dissolved or dispersed into the active material prior to the emulsification step. The anhydrous maleic polymers which are useful in the practice of this invention (i.e., those which contain a significant proportion of unhydrolyzed anhydride groups) will not ordinarily dissolve in the desirable detergent active materials. They can, however, be dispersed therein, and can be utilized in this manner if certain precautions are observed when they are used. It is preferred however, that the maleic polymers be actually dissolved into the polyoxyalkylene detergent active material. If the polymer has already been hydrolyzed, its dissolution into the active material generally requires that the two materials be physically blended for a few minutes. If the polymer has not already been substantially hydrolyzed, in order to dissolve it into the active material it must first be hydrolyzed, to yield essentially carboxylic acid groups along the polymer chain. Hydrolysis can be accomplished if desired, by simply exposing the powdered polymeric material to at least a stoichiometric amount of moisture, for example, in the form of water vapor, steam, or liquid water, for a sufficient length of time to hydrolyze enough of the anhydride groups that are present in the polymer chain so that the polymer can be dissolved in the detergent active material. It has been found that a very convenient, desirable, and preferred way to hydrolyze these polymers is to do so while they are dispersed through the detergent active material. Thus, the solution of polymer in active material results automatically when at least a certain proportion of the anhydride groups has been hydrolyzed. In order for the hydrolysis to take place within the mass of active material, at least about a stoichiometric amount of water (based on the total amount of anhydride groups present in the particular blend) must also be dissolved or dispersed through the polyoxyalkylene detergent active material. More than this minimum level of water can be present in the blend of active material plus polymer without detracting from the benefits that can be derived from practicing the invention, provided there is not sufficient moisture present to cause the polyoxyalkylene detergent active material to gel or lose its fluidity. Thus, for resins which are generally unhydrolyzed (which resins can be present in the active materials at levels of from about 0.5 to about 25 weight percent, and preferably at levels of from about 1 to about 15 weight percent, of the polyoxyalkylene detergent active material), usually from about 0.1 to about 4 weight percent, and preferably from about 0.3 to about 3 weight percent of water can also be dissolved into the active material. Although it is not presently known just what proportion of the anhydride groups in the maleic polymer must be hydrolyzed in order for the maleic polymers to be soluble in the polyoxyalkylene detergent active material, the actual degree of hydrolysis that is required need not be definitely known. This is due to the fact that whenever enough of the anhydride groups are hydrolyzed, the polymer simply dissolves in the detergent active material, resulting in a clear, homogeneous blend of polyoxyalkylene detergent active material, maleic polymer (which is largely hydrolyzed), and often a small amount of excess water. By using this preferred procedure, one can readily detect when the maleic polymer has been hydrolyzed, because a dispersion of unhydrolyzed polymer polyoxyalkylene material, which is initially opaque, becomes practically transparent when the resin has been sufficiently hydrolyzed (and concomitantly dissolved). The rate of hydrolysis of the maleic polymers within these preferred blends has been found to double with about each 10 C. rise in temperature.

Therefore, when it is desired to hydrolyze these resins quickly, the hydrolysis can be carried out at an elevated temperature. For example, although the polymer in one of these preferred blends can be hydrolyzed at ambient temperatures in about 1 to 48 hours, the time required for hydrolysis can be reduced to only about 30 minutes if the temperature of the blend is maintained at about 60 C. during the hydrolysis.

After the acidic maleic polymer has been dissolved into the polyoxyalkylene detergent active material via this preferred procedure, the resulting blend is then emulsified into an appropriate concentrated salt solution, as previously defined herein. The concentrated salt solution at this time can be either acidic, neutral or alkaline. But, since the invention requires that ultimately the pH of the liquid detergent product (after the emulsification step) be above about 8 and preferably above about 8.5 it is preferred that the concentrated salt solution have a pH above about 7 when one of the preferred blends described above is emulsified into it. In addition, for the production of final liquid detergent (emulsion) products having optimum stability to phase separation, the pH of the emulsion composition should be raised to at least about 8 before the tiny droplets of active material (which are at their smallest size just after the emulsification step) have had time or an opportunity otherwise to coalesce to a significant extent. Thus, the pH of the system should ordanirly be raised to at least about 8 within about and preferably within 3 hours of the time the active material is emulsified into the concentrated salt solution. When one of the preferred blends of maleic polymer plus active material is utilized, the concentrated salt solution can advantageously have a pH of at least about 8 at the time of the emulsification, so that the acidic polymer is converted to the alkali metal salt form practically as soon as it has migrated to the surface of the droplets of active material.

It has also been observed that the molecular weight of the particular maleic polymer that is utilized for this particular preferred process of the invention (involving the dissolution of the polymer into the active material before it is emulsified) has considerable import upon the relative ease with which the detergent active material can be emulsified into the concentrated salt solutions. Generally, polymers that have relatively higher molecular weights (other factors being about equal) require that extremely intense agitation be applied to the blends (of active material plus dissolved polymer) containing them, in order to produce emulsions having particles of a desirable size. Apparently, the presence of these higher molecular weight polymers causes the viscosity of the detergent active material to increase substantially, as compared to the viscosity of similar detergent active materials that contain the relatively lower molecular weight polymers. For this reason, it is preferred that maleic polymers having molecular weights between about 1,000 and about 50,000 and preferably between about 1,200 and about 35,000 be utilized in this particular aspect of the processes of the invention.

Because of the ease with which such blends of maleic polymers in the appropriate polyoxyalkylene detergent active materials can be utilized in the processes of this invention (as well as other reasons which will become apparent to those skilled in the art as a result of the present disclosure), a preferred embodiment of the invention is a composition consisting essentially of one of the polyoxyalkylene detergent active materials described above containing, preferably dissolved therein, from about 2 to about 25 weight percent of one of the acidic maleic polymers also described above. Particularly preferred are those polyoxyalkylene detergent active materials that are among the group consisting of alkylphenol, alcohol, and fatty acid condensates, (with ethylene oxide and/ or propylene oxide), which detergent active materials contain (preferably dissolved therein) from about 5 to about weight percent of an acidic maleic polymer which has a molecular weight within the range of from about 1,200 to about 35,000.

Examples I and 11 below, illustrate these preferred processes of the invention, wherein an acidic maleic polymer is dissolved into one of the polyoxyalkylene detergent active materials before the emulsification step. Example III below, illustrates another embodiment of these preferred processes, wherein the maleic polymer is dispersed into the detergent active material, but is hydrolyzed to the acid form during the emulsification step.

POLYMER IN SALT SOLUTION METHOD-I Another very desirable method by which the maleic polymer (in the acid form) is brought into intimate contact with the polyoxyalkylene detergent active material just at the time it is in its most finely divided state (in the concentrated salt solution) is by the polymer having been dissolved in the concentrated salt solution prior to the time the detergent active material is emulisfied thereinto. In order to maintain the polymer in the preferred acidic form until after the emulsification has been completed, the pH of the concentrated salt solution has to be maintained below about 7 and preferably below about 5, at least during the emulsification step.

The pH of the concentrated salt solutions can be maintained at such relatively low levels by any of a number of relatively simple means. For example, a concentrated salt solution containing about 5l0 weight percent of potassium sulfate or for that matter of practically any soluble and compatible inorganic alkali metal salt, and about 1 weight percent of sulfuric acid can be utilized to advantage in this process. Also, some of the anionic detergent active materials described heretofore, can be used in the acid form in order to achieve the desired acidity in the concentrated salt solutions. However, it is preferred that an acidic water soluble chain phosphate salt for example, one of the group consisting of sodium acid pyrophosphate, potassium acid pyrophosphate, tetrasodium monohydrogen tripolyphosphate and tripotassium dihydrogen tripolyphosphate be utilized in the preparation of the acidic concentrated salt solutions that have been found to be so valuable in the practice of this aspect of the invention.

Any of the useful maleic polymers described heretofore can be utilized in these particular processes by simply stirring the desired polymer or combination of polymers into one of the relatively acidic concentrations of salt solutions until the resulting mixture becomes practically clear. (The polymers will not usually dissolve in these aqueous salt solutions, but will, rather, become colloidally dispersed to the extent that the resulting solutions appear to be almost clear.)

Example IV, below, illustrates the processes of the invention, wherein the polymer (in the acid form) is dissolved in the concentrated salt solution prior to the emulsification step.

Sometimes when the polymer in salt solution method- I described above, is utilized, an unexpectedly high amount of energy is required in order to emulsify the detergent active material into the concentrated salt solution. It is believed that this difiiculty can be attributed to the use of relatively higher molecular weight maleic polymers, which cause the viscosity of the detergent active materials to increase when the polymers are apparently preferentially absorbed thereinto. Such potential ditficulty can be avoided by the use of polymers having relatively lower molecular weights. However, they can also be avoided by utilizing still another prc ferred process of the invention, termed the polymer in salt solution method-II as described below.

POLYMER IN SALT SOLUTION METHOD-II By this method, hydrolysis of the anhydride groups in the maleic I polymer and emulsification of the polyoxyalkylene detergent active material into the concentrated salt solution are performed practically simultaneously. The pH of the concentrated salt solutions is maintained below about 7 (and preferably below about while hydrolysis of the polymer and the emulsification of the detergent active material are taking place. Thus, ordinarily, from about 0.1 to about 5 (and preferably from about 0.25 to about 3) weight percent (based on the weight of the final liquid detergent product) of an anhydrous maleic polymer is initially mixed into one of the neutral or acidic concentrated salt solutions described above. Then, while the maleic polymer is undergoing hydrolysis, from about 2 to about weight percent of a polyoxyalkylene detergent active material is emulsified into the resulting mixture. Strong agitation is continued until at least a major portion (more than about half and preferably until substantially all) of the maleic polymer has been hydrolyzed. Then (usually Within about 2 hours, and preferably within about onehalf hour of the time the maleic polymer was dispersed into the concentrated salt solution), the pH of the resulting emulsion or suspension is increased to above about 8 and preferably to above about 8.5 to yield a final liquid detergent composition having excellent viscosity, drainage, and stability (to phase separation) characteristics. Example V below, illustrates this preferred process of the invention.

While it is preferred that polymers which are encompassed by the term maleic polymer be utilized in the processes of the present invention, it should be noted that the invention is not limited to the use of a maleic polymer. For example, any polymer which has a molecular weight of from about 1000 to about 100,000; contains carboxylic acid or carboxylic acid anhydride groups; is soluble (or can be made soluble by hydrolysis) in distilled water to the extent of at least about '1 weight percent; and is soluble (or can be made soluble by hydrolysis) in one of the polyoxyalkylene detergent active materials described herein to the extent of at least about 2 weight percent, can be utilized in the practice of this invention.

In the following examples all parts are by weight unless otherwise specified.

Example I Into a conventional mixing vessel fitted with a fairly efficient stirrer are charged 1,200 parts of a dodecylphenolethylene oxide condensate (containing an average of 12 moles of ethylene oxide per mole of dodecylphenol), 100 parts of Water and 100 parts of a linear ethylene-maleic anhydride polymer (having a molecular weight of about 1,500), and the maleic portions of which are almost entirely in the anhydride form. The resulting mixture is stirred well, and forms an opaque blend. The blend is then heated to 60 C. and held at this temperature for about 40 minutes. Within this time the blend has become transparent, indicating that the polymer has been hydrolyzed to the acid form, and has dissolved in the detergent active material. The resulting solution of acidic maleic polymer in dodecylphenol remains clear when it is cooled to room temperature.

While the foregoing dodecylphenol-polymer solution is being prepared, 11 parts of detergent grade sodium carboxymethylcellulose, 429 parts of water, 300 parts of tetrapotassium pyrophosphate and 120 parts of a sodium silicate solution having an SiO /Na O ratio of 2.5 (40 weight percent solids) are admixed in a separate conventional mixer, which is fitted with an Eppenbach-type mixer (which is a high-velocity, well baffied mixer that can develop to a very high degree of shear in the materials which are stirred thereby). These ingredients are stirred at a low mixer speed until the mixture becomes a clear (concentrated) salt solution. The pH of a 1 weight per- 10 cent solution of the resulting mixture in distilled water is about 10.

After the concentrated salt solution has been prepared, the speed of the mixer is increased so that a distinct vortex (leading into the blades of the mixer) is formed at the surface of the solution. Then parts of the polyoxyethylene alkylphenol-acidic maleic polymer blend (prepared above) are slowly poured into the vortex. The blend is thus emulsified into the concentrated salt solution. High speed mixing of the resulting emulsion is continued for about 10 minutes in order to assure that the polyoxyethylene detergent active material is well dispersed through the salt solution. The resulting final liquid detergent product is very fluid and very white in appearance. Most of the particles of detergent active material contained therein are less than 1p. in diameter.

In order to determine the stability to phase separation of this detergent, a sample of it is subjected to 1,000 times gravity for one and one-half hours in a centrifuge. At the end of this treatment, no phase separation is observed.

It will be noted that the liquid detergent product prepared according to Example I contains only 1 weight percent of the maleic polymer. The significant contribution of the particular processes of this invention can perhaps be better appreciated if one realized that a very similar liquid detergent product which is prepared by initially dissolving the maleic polymer into an otherwise identical concentrated salt solution and subsequently emulsifying the alkylphenol-ethylene oxide condensate into this solution, is significantly less stable to phase separation than is the detergent product prepared according to Example I (about 10 percent by volume of a clear layer can be observed at the bottom of the container after it has been subjected to 1,000 gs for one and one-half hours in a centrifuge).

It should also be noted that although in Example I above, all of the inorganic salts which are to be included in the final liquid detergent product were present in the concentrated salt solution at the time the emulsification was performed, it is only necessary that enough of the salts be present in the concentrated salt solution at this time, so that the particular polyoxyalkylene detergent active material that is utilized is substantially insoluble in the salt solution. That is, if an exceptionally stable detergent product is desired, the detergent active material should not ordinarily be soluble in the concentrated salt solution to the extent of more than about 12 Weight percent.

Example II A solution of 10 weight percent of an acidic (completely hydrolyzed) ethylene-maleic linear polymer (having a molecular weight of about 2,000) in the sodium salt of sulfonated dodecylbenzyl polyether of phenol (having 20 moles of propylene oxide plus 25 moles of ethylene oxide per mole of the phenol) is prepared by simply stirring at about 30 C. a mechanical blend of the individual ingredients until a clear solution is formed. The blend required about 10 minutes to clarify.

Then 16 parts of the resulting acidic polymer-polyoxyalkylene detergent active solution are poured into the vortex created by an Eppenbach mixer which is stirring at a very high speed a concentrated salt solution (prepared as in Example I, above) which contains 36.6 parts of water, 1.1 parts of sodium carboxymethylcellulose, 12 parts of sodium silicate solution having an SiO /Na O ratio of 2.0, and 6 parts of tetrapotassium pyrophosphate.

After the resulting emulsion is stirred for 10 minutes, 20 parts of a 60 weight percent solution of tetrapotassium pyrophosphate are added. The pH of the resulting final liquid detergent product (1 weight percent in distilled Water) is 10.2. Its stability (to phase separation) is ex cellent.

1 1 Example III A dispersion of 100 parts of an ethylene-maleic anhydride polymer (having a molecular weight of about 20,000) which has been partially cross-linked with vinyl crotonate in 1200 parts of a tridecanol-ethylene oxide condensation product which has been prepared by reacting 12 moles of ethylene oxide with 1 mole of highly branched tridecyl alcohol (prepared via the x0 process) is prepared by mixing together the two ingredients in a conventional mixing vessel. The dispersion remains opaque because there is not sufficient water present in the blend to hydrolyze enough of the anhydride groups in the polymer to solubilize it.

In a separate mixing vessel a concentrated salt solution having a pH of 3.6 is prepared by dissolving 5 parts of sodium acid pyrophosphate and 1.1 parts of sodium carboxymethylcellulose in 50.7 parts of water. While this salt solution is being stirred vigorously by means of a turbine type agitator, parts of the unhydrolyzed maleic polymer tridecanol-EO condensate prepared above is added slowly over a period of about 5 minutes. The vigorous stirring is continued for about 30 minutes, during which time the polymer is hydrolyzed. The temperature of the emulsion rises to about 50 C. due to the vigorous agitation. Then parts of tetrapotassium pyrophosphate are added. The pH of the solution is now 7.4. Then 6.2 parts of a 50 weight percent solution of potassium hydroxide, and 12 parts of sodium silicate solution are added. The pH of the resulting final liquid detergent product (measured at 1 weight percent in distilled water) is 10.2. Its stability toward phase separation is excellent.

It will be noted that in Example III, sufficient time was allotted during the emulsification step for the polymer to be hydrolyzed to the acid form before the pH of the emulsion was raised sufficiently to convert the acid form to the alkali metal salt. Ordinarily, the first of the two carboxylic acid groups (from the hydrolysis of maleic anhydride) is converted to the salt at a pH of about 5, while the second carboxylic acid group is converted at a pH above about 8.

Example IV A concentrated acidic salt solution is prepared by dissolving 500 parts of sodium acid pyrophosphate in 4,270 parts of water. To this solution are added 100 parts of a linear maleic anhydride-propylene polymer having a molecular weight of about 50,000. The resulting mixture is stirred for 45 minutes. Within this time the anhydride groups on the polymer have hydrolyzed, and a slightly hazy solution is produced. Its pH is 3.6. Then, while this acidic concentrated chain phosphate salt solution (containing the polymer) is agitated very vigorously (by means of a high speed mixer), 910 parts of a dodecylphenolethylene oxide adduct (containing about 10 moles of ethylene oxide per mole of the phenol), into which has been dispersed 100 parts of detergent grade sodium carboxymethylcellulose, are poured very slowly in the vortex created by the vigorous stirring. After about 10 minutes of such vigorous agitation, 2,500 parts of a 60 weight percent solution of tetrapotassium pyrophosphate are stirred into the emulsion, causing the pH of the emulsion to increase to 7.4. Then 620 parts of 50% KOH solution are also added, bringing the pH of the emulsion to 9.2. Finally 1,200 parts of a 40% solids (non-volatile at 105 C.) solution of sodium silicate having an SiO /Na O ratio of 2.5 are slowly stirred into the emulsion. The pH (measured at 1 weight percent in distilled water) of the resulting final liquid detergent product is 10.2. The stability of this product is excellent. Its stability to phase separation is considerably better than a comparable product that has been prepared using the same ingredients and identical process conditions, except that the pH of the concentrated salt solution is above 9.5 during the emulsifying step.

1 2 Example V A concentrated salt solution having a pH of 6.5 is prepared by dissolving 50 parts of sodium acid pyrophosphate and 70 parts of tetrapotassium pyrophosphate in 4,250 parts of water. To this solution is added 150 parts of an anhydrous linear ethylene-maleic anhydride polymer having a molecular weight of about 50,000. Then, over a period of 5 minutes (during which time the polymer-containing salt solution is agitated very vigorously by means of a high speed mixer) 900 parts of a condensation product of ethylene oxide and a highly branched tridecyl alcohol (containing about 15 moles of ethylene oxide per mole of alcohol) are added. The high-speed stirring is continued for 45 minutes during which time the polymer is hydrolyzed, and apparently absorbed into or onto the detergent active material. (The emulsified detergent active material forms a ball-like mass of particles which remain tightly-packed around the blade of the mixer away from the walls of the mixing vessel, while the viscosity of the salt solution increases only slightly during this time.)

Then while agitation is continued 2,500 parts of a 60 weight percent solution of tetrapotassium pyrophosphate are stirred into the emulsion, causing the pH of the emulsion to increase to 9. During the addition of the tetrapotassium pyrophosphate solution (described above), the ball like mass of detergent active particles is dispersed through the aqueous phase, resulting in the formation of an opaque, uniform emulsion. Finally, 700 parts of a 50% KOH solution, and 1,200 parts of a 40% solids solution of potassium silicate having an SiO /K O ratio of 2.0 are slowly stirred into the emulsion. The stability to phase separation of the resulting liquid detergent product is excellent.

Having thus described the invention and several specific embodiments thereof the following is claimed.

What is claimed is:

1. A process for manufacturing a liquid detergent composition, which process comprises (1) preparing an aqueous emulsion of (a) a water-soluble detergent active material containing a polyoxyalkylene chain in intimate contact with (b) an acidic copolymer of maleic anhydride and a lower molecular Weight olefinically unsaturated compound containing from 2 to 4 carbon atoms and having a molecular weight between about 26 and about the aqueous phase of said emulsion being a concentrated salt solution in which said detergent active material is substantially insolubie and containing, dissolved therein, at least about 3 weight percent of an inorganic alkali metal chain phosphate salt; said detergent active material being an alkoxylated detergent having from about 5 to about 50 alkylene oxide units in its polyoxyalkylated chain and being selected from the group consisting of reaction products of a lower alkylene oxide with an alkylphenol having an alkyl chain containing from about 6 to about 20 carbon atoms, a monohydric alcohol containing from about 10 to about 18 carbon atoms, a fatty acid containing from about 10 to about 18 carbon atoms and sulfates thereof, and said acidic copolymer having a molecular weight between 1000 and about 100,000; (2) subsequently converting said acidic copolymer to the alkaline salt form while said detergent active material is in the emulsified state.

2. A process as in claim 1 wherein said acidic copolymer is dissolved in said detergent active material before said emulsion is prepared.

3. A process as in claim 1 wherein said acidic copolymer is dissolved in said concentrated salt solution before said emulsion is prepared.

4. A process as in claim 1 wherein said acidic copolymer is formed in said process by hydrolyzing an anhydrous copolymer of maleic anhydride and a lower molecular weight olefinically unsaturated compound containing from 2 to 4 carbon atoms and having a molecular weight between about 26 and about 100 maleic polymer in said concentrated salt solution during the preparation of said emulsion; the molecular weight of said anhydrous copolymer being from about 1200 to about 50,000. 5. A process as in claim 1 wherein said acidic copolymer is a linear ethylene-maleic polymer and said alkali metal chain phosphate salt is selected from the group consisting of tetrasodium pyrophosphate, sodium acid pyrophosphate, tetrapotassium pyrophosphate, and potassium acid pyrophosphate.

6. A process for manufacturing a liquid detergent composition, which process comprises the steps of dissolving an acidic at least partially hydrolyzed copolymer of maleic anhydride and lower molecular weight olefinically unsaturated compound containing from 2 to 4 carbon atoms and having a molecular weight of from about 26 to about '60 in a polyoxyalkylene detergent active material, emulsifying the resulting solution of said copolymer in said detergent active material into an alkaline concentrated aqueous salt solution containing, dissolved therein, at

least about 3 weight percent of an inorganic alkali metal chain phosphate salt, thereby converting said copolymer tothe alkaline salt form before the resulting emulsion coalesces; the molecular weight of said copolymer being between about 1200 and about 50,000 and said detergent active material being an alkoxylated detergent having from about 5 to about 50 alkylene oxide units in its polyoxyalkylene chain and being selected from the group consisting of reaction products of a lower alkylene oxide .with an alkylphenol having an alkyl chain that contains from about 6 to about 20 carbon atoms, a monohydric alcohol containing from about 10 to about 18 carbon atoms, a fatty acid containing from about 10 to about 18 carbonatoms, and sulfates thereof.

7. A process for manufacturing a heavy duty liquid detergent emulsion composition, which process comprises the steps of first dissolving from about 2 to about 25 weight percent ofan acidic copolymer of' maleic anhydride and lower molecular weight olefinically unsaturated compound containing from 2 to 4 carbon atoms; said copolymer having a molecular weight within the range of from about 1200 to about 35,000 and said olefinically unsaturated compound having a molecular weight of from about 26 to about 60; into a water-soluble nonionic polyoxyalkylene detergent active material having from about 10 to about 25 oxyal kylene units in their polyoxyalkylene chains; said nonionic polyoxyalkylene detergent active materialbeing the reaction product of a lower alkylene oxide with a monohydric alcohol containing from about from about 2 to about 30 parts by weight of the resulting solution into 100 parts by weight of an aqueous solution of an alkali metalchain phosphate salt; said aqueous solution having a pH above about 8.5, and the concentration of said chain phosphate salt in said aqueous solution being at least about 3 weight percent, and such that said polyoxyalkylene detergent active material is substantially insoluble in said aqueous solution, and converting said acidic copolymer to the alkali metal salt form before the resulting emulsion coalesces.

8. A process as in claim 7, wherein said nonionic polyoxyalkylene detergent active material is the reaction product of a lower alkylene oxide with an alkylphenol having an alkyl group that contains from about 8 to about 20 carbon atoms.

9. A process as in claim 7, wherein said nonionic polyoxyalkylated detergent active material is the reaction product of a lower alkylene oxide with a fatty acid containing from about 10 to about 18 carbon atoms.

10. A process for manufacturing a heavy duty liquid detergent composition having a pH above about 8, which process comprises the steps of dissolving in a water soluble nonionic polyoxyethylene detergent active material having from about 10 to about 25 ethylene oxide units in its polyoxyethylene chain; said detergent active material being the reaction product of ethylene oxide with an alkylphenol having an alkyl group that contains from about 8 to about 20 carbon atoms; from about 2 to about 10 weight percent of a linear acidic lower molecular weight olefin-maleic anhydride copolymer having a molecular weight within the range of from about 1200 to about 35,000, said weight percent being based on the weight of said detergent active material and the molecular Weight of said olefin being between about 26 and about 60, and emulsifying from about 2 to about 20 parts by weight of the resulting solution into about parts by weight of an alkaline concentrated aqueous solution of an alkali metal chain phosphate salt wherein said alkali metal is selected from the group consisting of sodium and potassium.

11. A process as in claim 10 wherein said lower molecular weight olefin-maleic anhydride copolymer is an ethylene-maleic anhydride copolymer, and said water-soluble polyoxyethylene detergent active material is a condensate of dodecylphenol with from about 10 to about 35 moles of ethylene oxide per mole of dodecylphenol.

12. A process as in claim 11, wherein said detergent active material is the reaction product of ethylene oxide with a monohydric primary alcohol containing from about 10 to about 18 carbon atoms.

13. A process for manufacturing a liquid detergent composition which process comprises emulsifying from about 2 to about 20 parts by weight of a polyoxyalkylene detergent active material into about 100 parts by weight of an aqueous concentrated salt solution having a pH lower than about 7 and containing dissolved therein at least about 3 weight percent of an inorganic alkali metal chain phosphate salt and from about 0.1 to about 8 weight percent of an acidic copolymer of maleic anhydride and lower molecular weight olefinically unsaturated compound containing from 2 to 4 carbon atoms and having a molecular weight of from about 26 to about 60; said copolymer having a molecular weight of from about 1,000 to about 100,000 and said polyoxyalkylene detergent active material being substantially insoluble in said aqueous concentrated salt solution; and thereafter increasing the pH of the resulting emulsion to at least about 8; said detergent active material being an alkoxylated detergent having from about 5 to about 50 alkylene oxide units in its polyoxyalkylene chain and being selected from the group consisting of reaction products of a lower alkylene oxide with an alkylphenol having an alkyl group that contains from about 6 to about 20 carbon atoms, a monohydric alcohol containing from about 10 to about 18 carbon atoms, a fatty acid containing from about 10 to about 18 carbon atoms, and sulfates thereof.

14. A process for manufacturing a liquid detergent composition, which process comprises the steps of emulsifying from about 5 to about 15 parts by weight of a watersoluble nonionic polyoxyethylene detergent active material into about 100 parts by weight of an aqueous solution which contains from about 3 to about 20 weight percent of an acid pyrophosphate salt selected from the group consisting of sodium acid pyrophosphate and potassium acid pyrophosphate and from about 0.25 to about 3 weight percent of an acidic ethylene-maleic anhydride polymer having a molecular Weight of from about 1,500 to about 50,000, and thereafter adjusting the pH of the resulting emulsion to at least about 8 with potassium hydroxide; said detergent active material being an ethoxylated detergent having from about 5 to about 25 ethylene oxide units in its polyoxyethylene chain and being the reaction product of ethylene oxide with an alkylphenol having an alkyl group that contains from about .6 to about 20 carbon atoms.

15. A process as in claim 14, wherein said detergent active material is the reaction product of ethylene oxide with a monohydric primary alcohol containing from abo ut 10 to about 18 carbon atoms.

16. A process as in claim 14, wherein said detergent active material is the reaction product of ethylene oxide 15 with a fatty acid containing from about 10 to about 18 carbon atoms.

17. A process for manufacturing a liquid detergent composition, which process comprises the steps of simultaneously emulsifying from about 2 to about 20 parts by weight of a polyoxyalkylene detergent active material into about 100 parts by weight of a concentrated salt solution containing, dissolved therein, at least about 3 weight percent of an inorganic alkali metal chain phosphate salt, and having a pH below about 7 and hydrolyzing from about 0.15 to about 10 parts by weight of an anhydrous copolymer of maleic anhydride and an olefinically unsaturated aliphatic compound containing from 2 to 4 carbon atoms and having a molecular weight of from about 26 to about 60 in said salt solution; the molecular weight of said copolymer being within the range of from about 1,000 to about 100,000; said polyoxyalkylene detergent active material being substantially insoluble in said concentrated salt solution; and adjusting the pH of the resulting emulsion to above about 8 after said maleic polymer has been hydrolyzed; said detergent active material being an alkoxylated detergent having from about 5 to about 25 alkylene oxide units in its polyoxyalkylene chain and being selected from the group consisting of the reaction products of a lower alkylene oxide with alkylphenols having an alkyl group that contains from about 6 to about 20 carbon atoms, a monohydric alcohol containing from about 10 to about 18 carbon atoms, a fatty acid containing from about 10 to about 18 carbon atoms, and sulfates thereof.

18. A process for manufacturing a liquid detergent composition, which process comprises the steps of mixing into about 100 parts by weight of a concentrated salt solution having a pH below about 5 from about 0.25 to about 3 parts by weight of an anhydrous ethylene maleic anhydride copolymer having a molecular weight within the range of from about 1,500 to about 50,000, emulsifying into the resulting mixture from about 5 to about parts by weight of a water-soluble polyoxyethylene detergent active material, dissolving into the resulting emulsion from about 5 to about 40 parts by weight of a potassium chain phosphate salt, and adjusting the pH of the resulting emulsion to above about 8.5 after said copolymer has been hydrolyzed to the acid form; said detergent active material being an ethoxylated detergent having from about 5 to about ethylene oxide units in its polyoxyethylene chain and being the reaction product of ethylene oxide with an alkylphenol having an alkyl group that contains from about 6 to about 20 carbon atoms.

19. A process as in claim 18, wherein said detergent active material is the reaction product of ethylene oxide with a monohydric primary alcohol containing from about 10 to about 18 carbon atoms.

20. A process as in claim 18, wherein said detergent active material is the reaction product of a lower alkylene oxide with a fatty acid containing from about 10 to about 18 carbon atoms.

21. A process for producing an intermediate composition useful in the formulation of liquid detergent compositions, which process comprises intermixing from about 2 to about 25 parts by weight of a copolymer of maleic anhydride and lower molecular weight olefinically unsaturated compound containing from 2 to 4 carbon atoms and having a molecular Weight of from about 26 to about 100, said copolymer containing carboxylic anhydride groups and having a molecular weight of from about 1000 to about 100,000; with about parts by weight of a water-soluble nonionic polyoxyalkylene detergent active material having from about 10 to about 25 alkylene oxide units in its polyoxyalkylene chain and an amount of water which is at least the stoichiometric amount required to hydrolyze said anhydride groups, but less than the amount which will cause said detergent active material to gel, said detergent active material being the reaction product of a lower alkylene oxide with an alkylphenol having an alkyl group that contains from about 6 to about 20 carbon atoms.

22. A process as in claim 21, wherein said detergent active material is the reaction product of a lower alkylene oxide with a monohydric alcohol containing from about 10 to about 18 carbon atoms.

23. A process for manufacturing a heavy duty liquid detergent emulsion composition, which process comprises the steps of first dissolving from about 2 to about 25 Weight percent of an at least partially hydrolyzed ethylene-maleic anhydride copolymer having a molecular weight within the range of from about 1200 to about 35,000 into a condensation product of dodecylphenol with ethylene oxide having a molar ratio of dodecylphenol to ethylene oxide, respectively, of about 1:12, and thereafter emulsifying from about 2 to about 30 parts by weight of the resulting solution into 100 parts by weight of an aqueous solution containing dissolved therein at least about 3 weight percent of tetrapotassium pyrophosphate, and converting said copolymer to the potassium salt before the resulting emulsion coalesces.

References Cited by the Examiner UNITED STATES PATENTS 2,327,302 8/1943 Dittmar 26029.6 2,378,629 6/1945 Hanford 26078 2,921,930 l/l960 Suhrie 26078.5 3,060,124 10/1962 Ginn et al. 252l37 XR JULIUS GREENWALD, Primary Examiner. 

1. A PROCESS FOR MANUFACTURING A LIQUID DETERGENT COMPOSITION, WHICH PROCESS COMPRISES (1) PREPARING AN AQUEOUS EMULSION OF (A) A WATER-SOLUBLE DETERGENT ACTIVE MATERIAL CONTAINING A POLYOXYALKYLENE CHAIN IN INTIMATE CONTACT WITH (B) AN ACIDIC COPOLYMER OF AMLEIC ANHYDRIDE AND A LOWER MOLECULAR WEIGHT OF OLEFINICALLY UNSATURATED COMPOUND CONTAINING FROM 2 TO 4 CARBON ATOMS AND HAVING A MOLECULAR WEIGHT BETWEEN ABOUT 26 AND ABOUT 100; THE AQUEOUS PHASE OF SAID EMULSION BEING A CONCENTRATED SALT SOLUTION IN WHICH SAID DETERGENT ACTIVE MATERIAL IS SUBSTANTIALLY INSOLUBLE AND CONTAIING, DISSOLVED THEREIN, AT LEAST ABOUT 3 WEIGHT PERCENT OF AN INORGANIC ALKALI METAL CHAIN PHOSPHATE SALT; SAID DETERGENT ACTIVE MATERIAL BEING AN ALKOXYLATED DETERGENT HAVING FROM ABOUT 5 TO ABOUT 50 ALKYLENE OXIDE UNITS IN ITS POLYOXYALKYLATED CHAIN AND BEING SELECTED FROM THE GROUP CONSISTING OF REACTION PRODUCTS OF A LOWER ALKYLENE OXIDE WITH AN ALKYLPHENOL HAVING AN ALKYL CHAIN CONTAINING FROM ABOUT 6 TO ABOUT 20 CARBON ATOMS, A MONOHYDRIC ALCOHOL CONTAINING FROM ABOUT 10 TO ABOUT 18 CARBON ATOMS, A FATTY ACID CONTAINING FROM ABOUT 10 TO ABOUT 18 CARBON ATOMS AND SULFATES THEREOF, AND SAID ACIDIC COPOLYMER HAVING AMOLECULAR WEIGHT BETWEEN 1000 AND ABOUT 100,000; (2) SUBSEQUENTLY CONVERTING SAID ACIDIC COPOLYMER TO THE ALKALINE SALT FORM WHILE SAID DETERGENT ACTIVE MATERIAL IS IN THE EMULSIFIED STATE. 